1. The free edges of your fingernails and toenails are technically called the:

A. Lunula (The lunula is the white crescent moon shape at the base of the nail)
B. Matrix (The matrix is the area under the nail where new nail cells are produced)
C. Hyponychium (This is the skin under the free edge of the nail)
D. Free edge

Correct answer: D

Rationale: The free edges of your fingernails and toenails are the parts that extend beyond the fingertip or toe. These edges are commonly referred to simply as the "free edge" because they are not attached to the skin. The lunula is the white crescent moon shape at the base of the nail, the matrix is the area under the nail where new nail cells are produced, and the hyponychium is the skin under the free edge of the nail. Therefore, the correct answer is D.

2. Classifications of human tissues exclude:

A. Epithelial tissue
B. Nervous tissue
C. Adipose tissue (a specialized form of connective tissue)
D. Bony tissue

Correct answer: D

Rationale: The correct answer is D: 'Bony tissue.' Classifications of human tissues typically include four main types: epithelial, connective, muscular, and nervous tissue. Bony tissue, also known as osseous tissue, is a specialized form of connective tissue that forms bones in the skeletal system. While bony tissue is an essential component of the human body, it is not typically categorized separately as a distinct tissue type in general tissue classifications. Therefore, it is the exception from the list provided in the question, making it the correct answer.

3. Repeating decimals can be expressed as fractions. Which of the following represents the decimal 0.7777... as a fraction?

A. 77/1000
B. 70/99
C. 777/900
D. 7/9

Correct answer: C

Rationale: Let x equal the decimal. Set up two equations such that the digits after the decimal point are identical. 1000x = 777.7777... 10x = 7.7777... Subtracting the two equations, we have 990x = 770. Dividing both sides by 990 gives us x = 770/990, which can be simplified to 77/90.

4. A new material is claimed to be stronger than steel. You design an experiment to test this claim. What is the MOST important control variable?

A. The size of the material samples.
B. The temperature at which the test is conducted.
C. The force applied to the material.
D. The color of the material.

Correct answer: A

Rationale: The size of the material samples is the most important control variable because it ensures that the comparison between the new material and steel is fair and accurate. By keeping the size consistent, any differences in strength can be attributed to the material composition rather than variations in sample size. Controlling for size helps eliminate confounding variables and increases the reliability of the experiment results. Temperature, force applied, and color are not as critical for directly testing the strength comparison between the new material and steel.

5. Which digestive enzyme is primarily responsible for breaking down proteins?

A. Pepsin
B. Lipase
C. Amylase
D. Maltase

Correct answer: A

Rationale: The correct answer is A: Pepsin. Pepsin is primarily responsible for breaking down proteins in the stomach. It is an enzyme produced by the gastric chief cells in the stomach lining and works in a highly acidic environment to break down proteins into smaller peptide fragments. Lipase, on the other hand, is responsible for breaking down fats, amylase for breaking down carbohydrates, and maltase for breaking down maltose (a type of sugar). Therefore, pepsin is the correct enzyme involved in the digestion of proteins.

6. Which structure in the respiratory system serves as the "windpipe" that conducts air from the larynx to the bronchi?

A. Trachea
B. Larynx
C. Bronchi
D. Alveoli

Correct answer: A

Rationale: The correct answer is A: Trachea. The trachea, also known as the windpipe, is a tube-like structure in the respiratory system that connects the larynx to the bronchi. It serves as the main airway for the passage of air into and out of the lungs. The larynx is commonly known as the voice box and is responsible for producing sound. The bronchi are the two branches that stem from the trachea and lead to the lungs, where they further divide into smaller airways. The alveoli are tiny air sacs in the lungs where gas exchange occurs. Therefore, the trachea is the correct answer as it directly conducts air from the larynx to the bronchi.